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CCNA 2 v3.0 Module 7 Distance Vector Routing

Protocols

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Purpose of This PowerPoint

• This PowerPoint primarily consists of the Target Indicators (TIs) of this module in CCNA version 3.0.

• It was created to give instructors a PowerPoint to take and modify as their own.

• This PowerPoint is:

NOT a study guide for the module final assessment.

NOT a study guide for the CCNA certification exam.

• Please report any mistakes you find in this PowerPoint by using the Academy Connection Help link.

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To Locate Instructional Resource Materials on Academy Connection:

• Go to the Community FTP Center to locate materials created by the instructor community

• Go to the Tools section

• Go to the Alpha Preview section

• Go to the Community link under Resources

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• Search http://www.cisco.com

• Contact your parent academy!

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Objectives

• Distance vector routing

• RIP

• IGRP

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Distance Vector Updates

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Problem: Routing Loops

• Routing loops can occur when inconsistent routing tables are not updated due to slow convergence in a changing network.

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Problem: Counting to Infinity

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Solution: Defining a Maximum for Infinity

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Solution: Split Horizon

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Solution: Route Poisoning

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Solution: Triggered Updates

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Solution: Holddown Timers

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Key Characteristics of RIP

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RIP Commands

• Using router rip and network commands to Enable RIP

• Enabling RIP on an IP-addressed network

• Monitoring IP packet flow using the show ip protocol command

• The show ip route command

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Configuring RIP

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Using the ip classless Command

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RIP Configuration Issues

• To reduce routing loops and counting to infinity, RIP uses the following:

Defining infinity

Split horizon

Route poisoning & poison reverse

Triggered updates

Holddown timers

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The show ip protocols Command

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The show ip route Command

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Troubleshooting RIP Update Issues

• debug ip rip

• show ip rip database

• show ip protocols {summary}

• show ip route

• debug ip rip {events}

• show ip interface brief

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Preventing Routing Updates through an Interface

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Load Balancing with RIP

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Administrative Distance

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Integrating Static Route with RIP

• A router running RIP can receive a default route via an update from another router running RIP.

• Another option is for the router to generate the default route itself.

• The administrator can override a static route with dynamic routing information by adjusting the administrative distance values.

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IGRP Features

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IGRP Commands

• Using router igrp and network commands to enable IGRP

• Enabling IGRP on an IP-addressed network

• Monitoring IP packet flow using the show ip protocol command

• The show ip interfaces command

• The show ip route command

• The debug ip rip command

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IGRP Metrics

• Bandwidth – The lowest bandwidth value in the path

• Delay – The cumulative interface delay along the path

• Reliability – The reliability on the link towards the destination as determined by the exchange of keepalives

• Load – The load on a link towards the destination based on bits per second

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IGRP Routes: Interior, System, & Exterior

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IGRP Stability Features

• Holddowns, Split horizons, & Poison-reverse updates

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Configuring IGRP

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Migrating RIP to IGRP

1. Verify existing routing protocol (RIP) on the routers to be converted.

2. Configure IGRP on RouterA and RouterB

3. Enter show ip protocols on RouterA and RouterB

4. Enter show ip route on RouterA and RouterB

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Verifying IGRP Configuration

• Some commands for checking IGRP configuration are as follows:

show interface interface

show running-config

show running-config interface interface

show running-config | begin interface interface

show running-config | begin igrp

show ip protocols

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Troubleshooting IGRP

• The following commands are useful when troubleshooting IGRP:

show ip protocols {summary}

show ip route

debug ip igrp events IGRP protocol events

debug ip igrp transactions IGRP protocol transactions

ping

traceroute